User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36

Steps to reproduce:

1. install CalDAV account in Cpanel (Horde server) associated with an email account (possible under "check email" from cpanel and then going to Calendar settings")
2. enable this CalDAV account in THunderbird calendar

Actual results:

1. User sends me a calendar invite (they are the owner of the meeting)
2. I accept the calendar invite
3. Thunderbird switches the owner of the meeting to me
4. I automatically receive an invite email from myself
5. the meeting owner does not receive a confirmation email on its original invite from me, however does get a meeting 'update' from me, with me as the owner

Expected results:

1. User sends me a calendar invite (they are the owner of the meeting)
2. I accept the calendar invite
3. the invite is put into my calendar, with the meeting owner being the person who sent the invite
4. the person who sent the invite gets a confirmation + I am set to "attending meeting" in their calendar

ps see also:
https://bugs.horde.org/ticket/13664
https://forums.cpanel.net/threads/invitations-and-events-in-thunderbird-lightning-with-cpanel-caldav.596851/
https://forums.cpanel.net/threads/caldav-invitations-events-in-thunderbird-lightning.645529/

(In reply to Rik from comment #0)

Expected results:

1. User sends me a calendar invite (they are the owner of the meeting)
2. I accept the calendar invite
3. the invite is put into my calendar, with the meeting owner being the person who sent the invite
4. the person who sent the invite gets a confirmation + I am set to "attending meeting" in their calendar

Thanks Rik, those are reasonable expectations! ;-)

(In reply to Thomas D. (:thomas8) from comment #2)

Thanks Rik, those are reasonable expectations! ;-)

haha thanks, yeah it's a pity, i really love Thunderbird, but just had to switch my email accounts over to Outlook, because calendar invites are so everywhere these days

PS if someone picks this up: suggestion to test it with multiple email/calendar accounts. For the independent entrepreneurs among us, with multiple email accounts, it's important to be able to accept meeting invites to separate email/calendar accounts (so not to have 1 default calendar account that 'accepts' all meeting invites, regardless of the email account to which the invite was sent)

PS2: i am now wondering: if the person who sent the meeting had sent the meeting to an email address that matches the email address of the calendar account, perhaps then this error would not have occurred? Worth checking out perhaps (impossible for me, because my calendar account is different from my email accounts). So, it occurs at least for all invites sent to my email accounts that do not match the calendar account, perhaps also when they do match :)

Hi all,
I am exactly in this situation and cannot confirm business meetings without spamming all attendees with new invitations with me as organizer.
I have thunderbird 78.5.1 on windows 10.
I tried with add-in" CalDav & CardDav provider" and already had the issue. I added "TBSync" and I have the same issue.

I have a professionnal email address with its caldav calendar. Each time I accept a meeting, it sends out a new invite to all attendees with me as organizer.
I added my personnal email address with its caldav calendar and its now worse as it sends the new invite to all the attendees of my professionnal meeting with my personnal address as organizer.

To reply to @Rik, I tried your PS2, I receive invitations to the email adress that matches my pro calendar and still have the issue.

I accept all invitations from my phone now :-(

(In reply to Anne from comment #5)

Hi all,
I am exactly in this situation and cannot confirm business meetings without spamming all attendees with new invitations with me as organizer.
I have thunderbird 78.5.1 on windows 10.
I tried with add-in" CalDav & CardDav provider" and already had the issue. I added "TBSync" and I have the same issue.

John, any hints?

I have a professionnal email address with its caldav calendar. Each time I accept a meeting, it sends out a new invite to all attendees with me as organizer.

That's extremely odd!

I added my personnal email address with its caldav calendar and its now worse as it sends the new invite to all the attendees of my professionnal meeting with my personnal address as organizer.

Worse! Together with similar bug 1562896, this presents a serious failure and privacy violation, and we need to investigate if TB is causing this.

To reply to @Rik, I tried your PS2, I receive invitations to the email adress that matches my pro calendar and still have the issue.
I accept all invitations from my phone now :-(

Apologies Anne & anyone affected for the inconvenience.
We'll try to figure this out and fix it if it is under our control.
We're fixing and improving a lot of other things, too, so please bear with us a bit, but do give me a needinfo? ping if this doesn't get attention.

(In reply to Anne from comment #5)

Hi all,
I am exactly in this situation and cannot confirm business meetings without spamming all attendees with new invitations with me as organizer.
I have thunderbird 78.5.1 on windows 10.
I tried with add-in" CalDav & CardDav provider" and already had the issue. I added "TBSync" and I have the same issue.

I have a professionnal email address with its caldav calendar. Each time I accept a meeting, it sends out a new invite to all attendees with me as organizer.
I added my personnal email address with its caldav calendar and its now worse as it sends the new invite to all the attendees of my professionnal meeting with my personnal address as organizer.

To reply to @Rik, I tried your PS2, I receive invitations to the email adress that matches my pro calendar and still have the issue.

I accept all invitations from my phone now :-(

sounds like you have exactly the same problem as me, indeed!
PS(2) yeah I tried PS2 too and discovered that the problem is the same there too

PS3: i have the same problem as Anne, that I connected my personal email address with the CalDAV calendar, and that upon accepting meeting invites to work email addresses, TB sends out a new meeting request to the organizer from my personal address

This is into the blue: Maybe Thunderbird is always using the email entity connected to a calender to send invites and not the email entity which recieved the invite? Could you check if your work calender is connected to your work email entity?

Screenshot of calendar settings showing the connected entity.

(In reply to John Bieling (:TbSync) from comment #9)

This is into the blue: Maybe Thunderbird is always using the email entity connected to a calender to send invites and not the email entity which recieved the invite? Could you check if your work calender is connected to your work email entity?

this is precisely what happens
and also for ACCEPTING invites, so if the invite is sent to email1, but email2 is connected, then in accepting an email invite, email2 takes over as the organizer and sends a new email to the original organizer, that email2 is now the organizer.....

This is into the blue: Maybe Thunderbird is always using the email entity connected to a calender to send invites and not the email entity which recieved the invite? Could you check if your work calender is connected to your work email entity?

--> Good hint, it was mixed up! so it resolves the pro/personnal issue. But still send invites to all attendees

(In reply to Anne from comment #12)

This is into the blue: Maybe Thunderbird is always using the email entity connected to a calender to send invites and not the email entity which recieved the invite? Could you check if your work calender is connected to your work email entity?

--> Good hint, it was mixed up! so it resolves the pro/personnal issue. But still send invites to all attendees

but this does not solve the problem for all of us:) i have multiple work email adresses, for which i all need to be able to accept meetings (i contract for various organizations). With TB, i can only connect one of these email addresses to my calendar, which then becomes the default for all calendar appointments.

Does it reproduce with local calendars?
I just wonder "who" it is who sends what... the server or Thunderbird.

Hi Magnus,
Just tested your suggestion.

• I created a local calendar
• My gmail address invited my pro address to a meeting
• I accepted and chose my local calendar
• My gmail address received the "accepted" notification as expected

Now I retry with my caldav pro calendar

• My gmail address invites my pro address to a meeting
• I accept and choose my caldav pro calendar
• My gmail address and my pro address receive an email inviting me with my pro address as organizer
• I have an error "Le traitement du message a échoué. État : 80004005." with says that the message processing has failed (which is new to me)

(I try to get rid of google products, that's why I would be happy to have my calendars work fine :-) )

Does this happen also for version 91?

(In reply to Wayne Mery (:wsmwk) from comment #16)

Does this happen also for version 91?

I don't know, i stopped using Thunderbird because of this... With so many meeting invites being sent these days, it really was not workable any longer.

My reading would indicate this is an issue with Horde servers using V4. of Kronolith.

The following bugs appear relevant to this discussion, with ticket 3965 being the crucial one.
https://bugs.horde.org/ticket/3965 Resolved 18 December 2015
https://bugs.horde.org/ticket/13027 Resolved 27 May 2014
https://bugs.horde.org/ticket/13126 Resolved 22 April 2014

I realise this sounds like ancient history talking about 7 years old patches. But the Horde project appears to move rather slowly, with the last release of the component occurring as V4.2 in July 2014. Clearly, ticket 3965 was not included in that and shows as a "feature" for V5. https://www.horde.org/apps/kronolith/roadmap/ Unfortunately for affected Horde users, V5 remains unreleased.

So the question here is really. Does the Thunderbird project implement some sort of workaround? Can it even do anything, as it appears the caldav server is doing the switching post the acceptance of the invite?

Is this a valid bug? Magnus, for a decision or appropriate referral if I have it wrong.

https://bugs.horde.org/ticket/3965#c45 says H6, 5 years ago.
It does seem to be server side bug that they acknowledged and fix. That they didn't release yet this many years later would imply that project isn't exactly of good health... as an admin I'd be looking for alternatives.

I'd take a patch if someone provides it, but other than that, it doesn't seem worth pursuing.